mod_so: Provide more helpful LoadModule feedback when an error occurs.

(Backport of r520733)

Reviewed by: wrowe, rpluem, niq


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@539275 13f79535-47bb-0310-9956-ffa450edef68